Combined outer arm manufacturing for spring over pivot three arm switchable roller finger follower

ABSTRACT

A method of manufacturing outer arms of a three arm spring over pivot switchable roller finger follower. The method includes the steps of forming the outer arms of the switchable roller finger follower as a single unit, forming a material web between the outer arms, and separating the outer arms apart from each other. Also, an intermediate assembly of the outer arms of the three arm spring over pivot switchable roller finger follower is disclosed. The intermediate assembly has a first outer arm, a second outer arm, and a material web which extends between the outer arms, and adjoins the outer arms together.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of U.S. 61/594,760 filed Feb. 3, 2012, which is incorporated by reference herein.

FIELD OF INVENTION

The present invention relates generally to internal combustion engines and more particularly to a method of manufacture and an intermediate assembly of a three arm spring over pivot switchable roller finger follower.

BACKGROUND OF THE INVENTION

Various methods of producing components for internal combustion engines are known. Some common methods of manufacturing components for internal combustion engines include forming the components individually by, for example, casting or forging. After forming, these components are typically then finished machining before or after assembly. Alternatively, components for the internal combustion engine can be formed together and then separated by, for example, fracturing, sawing, or cutting. After the components are separated, any excess material can then be removed, and the surfaces connecting the components during forming are typically machined.

See, for example U.S. Pat. No. 7,250,070, which is directed to a method of forming a powder metal connecting rod that has a main body and a separable cap. The main body and cap are separated from each other by fracturing the main body and the cap. To fracture the main body and the cap, a tensile force is applied at a point of fracture between the main body and cap.

Also, see U.S. Patent Application No. 2010/0300390, for an example of a switchable roller finger follower.

SUMMARY OF THE INVENTION

The present invention is directed to a method of manufacturing outer arms of a three arm spring over pivot switchable roller finger follower. Also, the present invention is directed to an intermediate assembly of the outer arms of the three arm spring over pivot switchable roller finger follower.

In order to optimize a combustion cycle for an internal combustion engine, it is desirable to control a valve lift event with variations in timing and/or lift, In order to control the valve lift event with variations in timing and/or lift, an accurate manufacturing method of outer arms of the switchable roller finger follower is required. By forming the outer arms of the switchable roller finger follower as a single unit during the manufacturing process, the cost and time of manufacture of the outer arms are significantly reduced and the accuracy of the outer arms is improved as the outer arms are formed as mirror images of each other.

Broadly, the present invention can be defined as a method for manufacturing outer arms, of a switchable roller finger follower. The outer arms include a first outer arm, which has a first inner surface and a second outer arm, which has a second inner surface. The method comprises the steps of forming the first outer arm and the second outer arm of the switchable roller finger follower as a single unit, forming a material web between the first outer arm and the second outer arm, and separating the first outer arm from the second outer arm.

The first outer arm and the second outer arm are manufactured by casting or metal injection molding.

The first outer arm and the second outer arm are minor images of each other.

Also, the outer arms are separated by cracking, splitting, or cutting.

The material web holding the first outer arm and the second outer arm together is a seam, and the seam only substantially contacts the inner surface of the first outer arm and the inner surface of the second outer arm.

After being separated from each other, the outer arms can be assembled with other components of the switchable roller finger follower.

Additionally, the present invention broadly relates to an intermediate assembly of a three arm spring over pivot switchable roller finger follower. The intermediate assembly comprises a first outer arm having a first inner surface, a second outer arm having a second inner surface, and a material web extending between the first outer arm and the second outer arm. The material web adjoins the first outer arm and the second outer arm together.

The outer arms are manufactured by casting or metal injection molding.

The first outer arm and the second outer arm are mirror images of each other.

The material web holding the first outer arm and the second outer arm together is a seam and the material seam only substantially contacts the inner surface of the first outer ring and the inner surface of the second outer ring.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further understood and appreciated by reading the following description in conjunction with the accompanying drawings, in which:

FIG. 1 is perspective view of an outer arm unit of the present invention;

FIG. 2 is a second perspective view of the outer arm unit;

FIG. 3 is a perspective view of the outer arms;

FIG. 4 is another perspective view of the outer arms; and

FIG. 5 is a further perspective view of the outer arms.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a perspective view of an outer arm unit 10. The outer arm unit 10 includes a first outer arm 12, a second outer arm 14 and a seam or web of material 16, which holds the first outer arm 12 and the second outer arm 14 together. The web is formed between the first outer arm 12 and the second outer arm 14. Preferably, the outer arm unit 10 is manufactured by cast or metal injection molded as a single unit. However, any other known method of manufacturing the outer arm unit 10 can also be used.

FIG. 2 illustrates a second perspective view of the outer arm unit 10. Here it can be seen that the seam or weld of material 16 does not contact at least part of an inner surface 18 of the first outer arm and at least part of an inner surface 20 of the second outer arm.

As shown in FIGS. 1 and 2, the outer arm unit 10 illustrates the first outer arm 12 and the second outer arm 14 prior to the first outer arm 12 and the second outer arm 14 being separated from each other. By manufacturing the outer arms 12, 14 as a single outer arm unit 10, the cost of manufacturing and the volume of manufacturing are significantly reduced. Also, the outer arms 12, 14 are more accurately manufactured.

In FIG. 3, the outer arms 12, 14 are shown after being separated from one another. FIG. 4 is an alternative perspective view of the outer arms 12, 14.

The outer arms 12, 14 can be separated from each other, for example, by cutting, cracking, or splitting the outer arms 12, 14 apart from each other so as to form two identical parts. As shown in FIG. 5, after separating the outer arms 12, 14 some of the seam or weld of material 16 remains.

The present invention has been described with reference to a preferred embodiment. It should be understood that the scope of the present invention is defined by the claims and is not intended to be limited to the specific embodiment disclosed herein.

LIST OF REFERENCE NUMERALS

-   10 Outer Arm Unit -   12 First Outer Arm -   14 Second Outer Arm -   16 Material -   18 Inner Surface -   20 Inner Surface 

What is claimed:
 1. A method for manufacturing outer arms, of a switchable roller finger follower, the outer arms including a first outer arm having a first inner surface and a second outer arm having a second inner surface, the method comprising the following steps: forming the first outer arm and the second outer arm of the switchable roller finger follower as a single unit; forming a material web between the first outer arm and the second outer arm; and separating the first outer arm from the second outer arm.
 2. The method of claim 1, wherein the outer arms are separated by cracking, splitting, or cutting.
 3. The method of claim 1, wherein the first outer arm and the second outer arm are mirror images of each other.
 4. The method of claim 1, wherein the first outer arm and the second outer arm are manufactured by casting or metal injection molding.
 5. The method of claim 1, wherein the material web holding the first outer arm and the second outer arm together is a seam.
 6. The method of claim 5, wherein the seam only substantially contacts the inner surface of the first outer arm and the inner surface of the second outer arm.
 7. The method of claim 1, further comprising the step of assembling the outer arms with other components of the switchable roller finger follower after the outer arms are separated from each other.
 8. An intermediate assembly of a three arm spring over pivot switchable roller finger follower, comprising: a first outer arm having a first inner surface; a second outer arm having a second inner surface; and a material web extending between the first outer arm and the second outer arm, and adjoining the first outer arm and the second outer arm together.
 9. The intermediate assembly of claim 7, wherein the first outer arm and the second outer arm are manufactured by casting or metal injection molding.
 10. The intermediate assembly of claim 7, wherein the first outer arm and the second outer arm are mirror images of each other.
 11. The intermediate assembly of claim 7, wherein the material web holding the first outer arm and the second outer arm together is a seam.
 12. The intermediate assembly of claim 7, Wherein the material seam only substantially contacts the inner surface of the first outer ring and the inner surface of the second outer ring.
 13. The intermediate assembly of claim 7, wherein the first outer arm and the second outer arm are mirror images of each other. 